Apps · Choosing which apps to move
Should I offload or uninstall an app I don't need right now?
Short answer: Offload it if you might want it back with your settings intact; Uninstall it if you're sure you're finished with it, so it uses no space anywhere.
If there's any chance you'll want it back — with your settings exactly as they were — Offload it: it frees the space and Restore is one click. If you're sure you're done with it, Uninstall it so it stops using space on your fast drive too.
Both are recoverable in the short term: uninstalled items sit in the Trash until you empty it.